Ischemic heart disease causes mitral regurgitation by the combination of ischemic dysfunction of the papillary muscles, and the dilatation of the left ventricle that is present in ischemic heart disease, with the subsequent displacement of the papillary muscles and the dilatation of the mitral valve annulus.
Dilation of the annulus of the mitral valve prevents the valve leaflets from fully coapting when the valve is closed. Mitral regurgitation of blood from the left ventricle into the left atrium results in increased total stroke volume and decreased cardiac output, and ultimate weakening of the left ventricle secondary to a volume overload and a pressure overload of the left atrium.
US 2007/0299424 to Cumming et al. describes a catheter assembly includes an inner liner made of flexible material and an outer layer having a steering mechanism. The steering mechanism includes at least one flat wire and a corresponding lumen through which the flat wire may travel. The steering mechanism may also include at least one pull ring to which the flat wires are attached. A layer of heat shrink material may encompass the outer layer. A braided wire assembly, which may have a braid density that varies along the length of the catheter, may also be provided in the outer layer. The overall cross-section of the catheter assembly is preferably substantially circular. A catheter shaft may include a plurality of segments of differing hardness characteristics. The outer layer typically comprises a melt processing polymer such that the catheter assembly may be laminated using heat.
PCT Publication WO 96/40344 to Stevens-Wright et al. describes a bidirectional steering catheter comprising a distal electrode assembly, a flexible tip assembly, an elongated shaft having a central lumen running the length of the shaft, and a handle/actuator. A plurality of ring electrodes are attached to the surface of the flexible tip assembly. Signal wires running the length of the catheter are electrically connected to each ring electrode. At least two pull cables having first and second ends extend distally through the central lumen. The first end of each pull cable is attached to the handle/actuator. The second end of each pull cable is attached to the distal electrode assembly, such that the distal electrode assembly may be moved between a first and second position within a single plane by manipulating the handle/actuator. At least two reinforcement members are located inside the flexible tip assembly. Each reinforcement member has a proximal section, a middle section and a distal section. Each proximal section has a larger diameter than each middle section, thus being stiffer than the middle section. This variable stiffness along the length of each reinforcement member distributes stresses evenly along the length of the tip assembly.
US 2005/0004668 to Aklog et al. describes implantable devices and methods for the repair of a defective cardiac valve. The implantable devices include an annuloplasty ring and a restraining and/or a remodeling structure or mechanism. The annuloplasty ring functions to reestablish the normal size and shape of the annulus bringing the leaflets in proximity to each other. A device having a remodeling structure further facilitates remodeling of the valve but allows the use of a flexible ring. The restraining structure functions to restrain the abnormal motion of at least a portion of the valve being repaired. The restraining and remodeling structures may include at least one strut across the interior of the circumference of the ring.
US 2005/0171601 to Cosgrove describes an annuloplasty repair segment and template for heart valve annulus repair. The elongate flexible template may form a distal part of a holder that also has a proximal handle. Alternatively, the template may be releasably attached to a mandrel that slides within a delivery sheath, the template being released from the end of the sheath to enable manipulation by a surgeon. A tether connecting the template and mandrel may also be provided. The template may be elastic, temperature responsive, or multiple linked segments. The template may be aligned with the handle and form a two- or three-dimensional curve out of alignment with the handle such that the annuloplasty repair segment attached thereto conforms to the curve. The template may be actively or passively converted between its straight and curved positions. The combined holder and ring are suited for minimally-invasive surgeries in which the combination is delivered to an implantation site through a small access incision with or without a cannula, or through a catheter passed through the patient's vasculature.
U.S. Pat. No. 6,102,945 to Campbell describes a support ring for a natural human heart valve, including a first ring portion having opposite terminal ends and a second ring portion having opposite terminal ends. An interconnector extends through and interconnects the first and second ring portions, to maintain the opposite terminal ends of the first ring portion adjacent the opposite terminal ends of the second ring portion, to form a segmented ring having a first and a second interface between the first and second ring portions. The first ring portion is of a greater length than the second ring portion. The ring portions are separable by severing the interconnector at the first and second interfaces, thus producing two variable size ring segments.
U.S. Pat. No. 5,593,424 to Northrup III describes an apparatus and method for reducing the circumference of a vascular structure comprising the steps of providing a plurality of sutures and a plurality of discrete suture support segments of a biocompatible, inert material. Each suture support segment has at least two suture holes spaced a predetermined distance apart. The method includes individually suturing each discrete suture support segment to the vascular structure with one of the plurality of sutures by effecting a horizontal mattress (U-shaped) suture along the vascular structure through a length of tissue of the vascular structure such that the length (D′) of tissue sutured is greater than distance (D); and tightening and tying off the suture, whereby each sutured suture support segment creates an imbrication in the vascular structure, thereby reducing the circumference thereof. A biocompatible, inert stabilizing material is described as being optionally affixed over the suture support segments and the vascular structure prior to tying off the suture to stabilize the interval between the suture support segments and eliminate direct exposure of the segmented apparatus to blood.
The following patents and patent applications may be of interest:    EP Patent EP 06/14342 to Pavcnik et al.    E P Patent EP 10/06905 to Organ    PCT Publication WO 00/22981 to Cookston et al.    PCT Publication WO 01/26586 to Seguin    PCT Publication WO 01/56457 to Pruitt    PCT Publication WO 03/047467 to Cosgrove et al.    PCT Publication WO 04/103434 to Martin et al.    PCT Publication WO 05/046488 to Douk et al.    PCT Publication WO 06/012013 to Rhee et al.    PCT Publication WO 06/012038 to Shaoulian et al.    PCT Publication WO 06/086434 to Powell et al.    PCT Publication WO 06/097931 to Gross et al.    PCT Publication WO 06/105084 to Cartledge et al.    PCT Publication WO 07/011799 to Navia et al.    PCT Publication WO 07/121314 to Rafiee et al.    PCT Publication WO 07/136981 to Cumming et al.    PCT Publication WO 96/39963 to Abela et al.    PCT Publication WO 97/01369 to Taylor et al.    PCT Publication WO 98/46149 to Organ    U.S. Pat. No. 3,656,185 to Carpentier    U.S. Pat. No. 4,961,738 to Mackin    U.S. Pat. No. 5,306,296 to Wright et al.    U.S. Pat. No. 5,325,845 to Adair    U.S. Pat. No. 5,716,370 to Williamson, IV et al.    U.S. Pat. No. 5,855,614 to Stevens et al.    U.S. Pat. No. 6,074,401 to Gardiner et al.    U.S. Pat. No. 6,524,338 to Gundry    U.S. Pat. No. 6,533,772 to Sherts et al.    U.S. Pat. No. 6,569,198 to Wilson et al.    U.S. Pat. No. 6,619,291 to Hlavka et al.    U.S. Pat. No. 6,626,899 to Houser et al.    U.S. Pat. No. 6,629,534, PCT Publication WO 06/116558 and US 2004/0039442 to St. Goar et al.    U.S. Pat. No. 6,752,813 to Golfarb et al.    U.S. Pat. No. 6,764,510 to Vidlund et al.    U.S. Pat. No. 6,893,459 to Macoviak    U.S. Pat. No. 6,918,917 to Nguyen et al.    U.S. Pat. No. 6,926,730 to Nguyen et al.    U.S. Pat. No. 6,986,775 to Morales et al.    U.S. Pat. No. 7,004,176 to Lau    U.S. Pat. No. 7,101,395 to Tremulis et al.    U.S. Pat. No. 7,150,737 to Purdy et al.    U.S. Pat. No. 7,172,625 to Shu et al.    U.S. Pat. No. 7,175,660 to Cartledge et al.    U.S. Pat. No. 7,220,277 to Arru et al.    U.S. Pat. No. 7,226,467 to Lucatero et al.    US 2001/0021874 to Capentier    US 2002/0198586 to Inoue    US 2003/0050693 to Quijano et al.    US 2003/0078465 to Pal et al.    US 2003/0114901 to Loeb et al.    US 2003/0191528 and U.S. Pat. No. 6,805,711 to Quijano et al.    US 2003/0199974 to Lee et al.    US 2004/0127983 to Mortier et al.    US 2004/0138744 to Lashinski et al.    US 2004/0148021 to Cartledge et al.    US 2004/0193191 to Starksen et al.    US 2004/0236419 to Milo    US 2004/0243227 to Starksen et al.    US 2004/0260394 to Douk et al.    US 2005/0055038 to Kelleher et al.    US 2005/0096740 to Langberg et al.    US 2005/0222678 to Lashinski et al.    US 2005/0288778 to Shaoulian et al.    US 2005/0288781 to Moaddeb et al.    US 2006/0095009 to Lampropoulos et al.    US 2006/0195134 to Crittenden    US 2006/0282161 to Huynh et al.    US 2006/0247763 to Slater    US 2007/0080188 to Spence et al.    US 2007/0244556 to Rafiee et al.    US 2007/0299424 to Cumming et al.    US 2008/0027483 to Cartledge et al.    US 2004/0148019 and US 2004/0148020 to Vidlund et al.    US 2004/0260393 to Randert et al. and US 2004/0127982 to Machold et al.    US 2005/0010287 and 2004/0138745 to Macoviak et al.
The following articles may be of interest:    O'Reilly S et al., “Heart valve surgery pushes the envelope,” Medtech Insight 8(3): 73, 99-108 (2006)    Dieter R S, “Percutaneous valve repair: Update on mitral regurgitation and endovascular approaches to the mitral valve,” Applications in Imaging, Cardiac Interventions, Supported by an educational grant from Amersham Health pp. 11-14 (2003)    Swain C P et al., “An endoscopically deliverable tissue-transfixing device for securing biosensors in the gastrointestinal tract,” Gastrointestinal Endoscopy 40(6): 730-734 (1994)    Odell J A et al., “Early Results of a Simplified Method of Mitral Valve Annuloplasty,” Circulation 92:150-154 (1995)